As discussed in U.S. Pat. No. 3,628,213, which is also assigned to Abington Textile Machinery Works, it is desirable in vacuum cleaning devices to clear the tank after each collection of lint and debris has been delivered thereto. This clearing cycle can of course be altered to be after every two or three deliveries. Also, the arrangement may include a plurality of receiving tanks which may alternately receive the collected residue.
It has been found that the lint and other residue tend to collect on the screen which separates the dome and collection tank. Should the screen become clogged, it must be replaced. This requires down time and loss of production.
Attempts have been made to provide screen cleaning air knives. To date, these have not been entirely satisfactory due to the large volume of air required to remove the residue. Also, there have been problems with wind sheer and noise.
Prior U.S. Pat. Nos. 3,377,780, 4,036,613, and 4,810,270 illustrate various types of air knives used to clean screens in filter apparatus and fiber separating apparatus. These types of air knives have been found to be unsatisfactory for use with vacuum cleaning devices of the type disclosed.
It is an object of the present invention to overcome the disadvantages of the systems as above set forth.
It is another object of the invention to provide an air knife cleaning system which operates with a minimum of compressed air while at the same time producing a cleaning curtain of air of large volume.
It is another object of the invention to provide a screen cleaning apparatus capable of effecting cleaning cycles every five minutes.
It is another object of the invention to provide a screen cleaning system which will integrate into the cyclic operation of the vacuum cleaning system.
It is another object of the invention to provide a screen cleaning system which will also assist in the removal of residue from the receiving tank.